Ligong Wang

activity

20152023

most citedOrdering of bicyclic graphs by matching energy

7 citations · 33 across the 43 of their papers we have counts for

collaborators

45 papers

math.CO2023

Fractional revival on semi-Cayley graphs over abelian groups

Jing Wang, Ligong Wang, Xiaogang Liu

In this paper, we investigate the existence of fractional revival on semi-Cayley graphs over finite abelian groups. We give some necessary and sufficient conditions for semi-Cayley…

math.CO2023

Sharp bounds for Laplacian spectral moments of digraphs with a fixed dichromatic number

Xiuwen Yang, Hajo Broersma, Ligong Wang

The $k$ -th Laplacian spectral moment of a digraph $G$ is defined as $\sum_{i = 1}^{n} λ_{i}^{k}$ , where $λ_{i}$ are the eigenvalues of the Laplacian matrix of $G$ and $k$ is a nonnegative in…

math.CO2023★ 1 cited

The sufficient conditions for $k$ -leaf-connected graphs in terms of several topological indices

Tingyan Ma, Ligong Wang, Yang Hu

Let $G = (V (G), E (G))$ be a graph with vertex set $V (G)$ and edge set $E (G)$ . For $k \geq 2$ and given any subset $S \subseteq ∣ V (G) ∣$ with $∣ S ∣ = k$ , if a graph $G$ of order $|V(G)|\geq k…

math.CO2022

An improvement of sufficient condition for $k$ -leaf-connected graphs

Tingyan Ma, Guoyan Ao, Ruifang Liu +2

For integer $k \geq 2,$ a graph $G$ is called $k$ -leaf-connected if $∣ V (G) ∣ \geq k + 1$ and given any subset $S \subseteq V (G)$ with $∣ S ∣ = k,$ $G$ always has a spanning tree $T$ such that…

math.CO2022

The $A_{α}$ spectral radius with given independence number $n - 4$

Xichan Liu, Ligong Wang

Let $G$ be a graph with adjacency matrix $A (G)$ and degree diagonal matrix $D (G)$ . In 2017, Nikiforov [Appl. Anal. Discrete Math., 11 (2017) 81--107] defined the matrix $A_α(G) =…

math.CO2022

The $A_{α}$ spectral radius of $k$ -connected graphs with given diameter

Xichan Liu, Ligong Wang

Let $G$ be a graph with adjacency matrix $A (G)$ and degree diagonal matrix $D (G)$ . In 2017, Nikiforov defined the matrix $A_{α} (G) = α D (G) + (1 - α) A (G)$ for any real $α \in [0, 1]$ . The…

math.CO2022

Fractional revival on Cayley graphs over abelian groups

Jing Wang, Ligong Wang, Xiaogang Liu

In this paper, we investigate the existence of fractional revival on Cayley graphs over finite abelian groups. We give a necessary and sufficient condition for Cayley graphs over f…

math.CO2022

Signless Laplacian Estrada index and Laplacian Estrada index of uniform hypergraphs

Cunxiang Duan, Edwin R. van Dam, Ligong Wang

We generalize the notions of Laplacian and signless Laplacian Estrada index to uniform hypergraphs. For an $r$ -uniform hypergraph $H,$ we derive an order $r + 1$ trace formula of the…

math.CO2022

Linear Turán numbers of acyclic quadruple systems

Lin-Peng Zhang, Ligong Wang

A linear $r$ -uniform hypergraph is called acycilc if it can be constructed starting from one single edge then at each step adding a new edge that intersect the union of the vertice…

math.CO2021★ 5 cited

On a conjecture of Nikiforov involving a spectral radius condition for a graph to contain all trees

Xiangxiang Liu, Hajo Broersma, Ligong Wang

We partly confirm a Brualdi-Solheid-Turán type conjecture due to Nikiforov, which is a spectral radius analogue of the well-known Erdős-Sós Conjecture that any tree of order $t$ is…

math.CO2021

Growth rates of the bipartite Erdős-Gyárfás function

Xihe Li, Hajo Broersma, Ligong Wang

Given two graphs $G, H$ and a positive integer $q$ , an $(H, q)$ -coloring of $G$ is an edge-coloring of $G$ such that every copy of $H$ in $G$ receives at least $q$ distinct colors.…

math.CO2021★ 4 cited

Spectral radius conditions for the existence of all subtrees of diameter at most four

Xiangxiang Liu, Hajo Broersma, Ligong Wang

Let $μ (G)$ denote the spectral radius of a graph $G$ . We partly confirm a conjecture due to Nikiforov, which is a spectral radius analogue of the well-known Erdős-Sós Conjecture th…

math.CO2021

On the $A_{α}$ spectral radius and $A_{α}$ energy of non-strongly connected digraphs

Xiuwen Yang, Ligong Wang

Let $A_{α} (G)$ be the $A_{α}$ -matrix of a digraph $G$ and $λ_{α 1}, λ_{α 2}, \dots, λ_{α n}$ be the eigenvalues of $A_{α} (G)$ . Let $ρ_{α} (G)$ be the $A_{α}$ spectral radius of $G$ and $E_α(G)=…

math.CO2021

On the $A_{α}$ spectral radius of strongly connected digraphs

Weige Xi, Ligong Wang

Let $G$ be a digraph with adjacency matrix $A (G)$ . Let $D (G)$ be the diagonal matrix with outdegrees of vertices of $G$ . Nikiforov \cite{Niki} proposed to study the convex combinat…

math.CO2020★ 1 cited

The Erdős-Gyárfás function with respect to Gallai-colorings

Xihe Li, Hajo Broersma, Ligong Wang

For fixed $p$ and $q$ , an edge-coloring of the complete graph $K_{n}$ is said to be a $(p, q)$ -coloring if every $K_{p}$ receives at least $q$ distinct colors. The function $f(n, p, q)…

math.CO2020★ 1 cited

The generalized Turán number of spanning linear forests

Lin-Peng Zhang, Ligong Wang, Jiale Zhou

Let $F$ be a family of graphs. A graph $G$ is called \textit{ $F$ -free} if for any $F \in F$ , there is no subgraph of $G$ isomorphic to $F$ . Given a gra…

math.CO2020

The bounds of the spectral radius of general hypergraphs in terms of clique number

Cunxiang Duan, Ligong Wang

The spectral radius (or the signless Laplacian spectral radius) of a general hypergraph is the maximum modulus of the eigenvalues of its adjacency (or its signless Laplacian) tenso…

math.CO2020

Extremal problems and results related to Gallai-colorings

Xihe Li, Hajo Broersma, Ligong Wang

A Gallai-coloring (Gallai- $k$ -coloring) is an edge-coloring (with colors from ${1, 2, \dots, k}$ ) of a complete graph without rainbow triangles. Given a graph $H$ and a positive…

math.CO2020

Iota energy orderings of bicyclic signed digraphs

Xiuwen Yang, Ligong Wang

The concept of energy of a signed digraph is extended to iota energy of a signed digraph. The energy of a signed digraph $S$ is defined by $E (S) = \sum_{k = 1}^{n} ∣ Re (z_{k}) ∣$ , wher…

math.CO2019

Gallai-Ramsey numbers for rainbow paths

Xihe Li, Pierre Besse, Colton Magnant +2

Given graphs $G$ and $H$ and a positive integer $k$ , the \emph{Gallai-Ramsey number}, denoted by $g r_{k} (G : H)$ is defined to be the minimum integer $n$ such that every coloring o…

math.CO2018

The generalized distance matrix of digraphs

Weige Xi, Wasin So, Ligong Wang

Let $D (G)$ and $D^{Q} (G) = D ia g (T r) + D (G)$ be the distance matrix and distance signless Laplacian matrix of a simple strongly connected digraph $G$ , respectively, where $Diag(Tr)=\te…

math.CO2018★ 1 cited

Gallai-Ramsey numbers for a class of graphs with five vertices

Xihe Li, Ligong Wang

Given two graphs $G$ and $H$ , the $k$ -colored Gallai-Ramsey number $g r_{k} (G : H)$ is defined to be the minimum integer $n$ such that every $k$ -coloring of the complete graph on $n$ …

math.CO2018★ 1 cited

Forbidden rainbow subgraphs that force large monochromatic or multicolored k-connected subgraphs

Xihe Li, Ligong Wang

Let $n, k, m$ be positive integers with $n ≫ m ≫ k$ , and let $A$ be the set of graphs $G$ of order at least 3 such that there is a $k$ -connected monochromatic subgraph…

math.CO2018★ 3 cited

Merging the A- and Q-spectral theories for digraphs

Weige Xi, Wasin So, Ligong Wang

Let $G$ be a digraph and $A (G)$ be the adjacency matrix of $G$ . Let $D (G)$ be the diagonal matrix with outdegrees of vertices of $G$ . For any real $α \in [0, 1]$ , Liu et al. \cite{LWC…

Fractional revival on semi-Cayley graphs over abelian groups

Sharp bounds for Laplacian spectral moments of digraphs with a fixed dichromatic number

The sufficient conditions for k-leaf-connected graphs in terms of several topological indices

An improvement of sufficient condition for k-leaf-connected graphs

The Aα​ spectral radius with given independence number n−4

The Aα​ spectral radius of k-connected graphs with given diameter

Fractional revival on Cayley graphs over abelian groups

Signless Laplacian Estrada index and Laplacian Estrada index of uniform hypergraphs

Linear Turán numbers of acyclic quadruple systems

On a conjecture of Nikiforov involving a spectral radius condition for a graph to contain all trees

Growth rates of the bipartite Erdős-Gyárfás function

Spectral radius conditions for the existence of all subtrees of diameter at most four

On the Aα​ spectral radius and Aα​ energy of non-strongly connected digraphs

On the Aα​ spectral radius of strongly connected digraphs

The Erdős-Gyárfás function with respect to Gallai-colorings

The generalized Turán number of spanning linear forests

The bounds of the spectral radius of general hypergraphs in terms of clique number

Extremal problems and results related to Gallai-colorings

Iota energy orderings of bicyclic signed digraphs

Gallai-Ramsey numbers for rainbow paths

The generalized distance matrix of digraphs

Gallai-Ramsey numbers for a class of graphs with five vertices

Forbidden rainbow subgraphs that force large monochromatic or multicolored k-connected subgraphs

Merging the A- and Q-spectral theories for digraphs

The sufficient conditions for $k$ -leaf-connected graphs in terms of several topological indices

An improvement of sufficient condition for $k$ -leaf-connected graphs

The $A_{α}$ spectral radius with given independence number $n - 4$

The $A_{α}$ spectral radius of $k$ -connected graphs with given diameter

On the $A_{α}$ spectral radius and $A_{α}$ energy of non-strongly connected digraphs

On the $A_{α}$ spectral radius of strongly connected digraphs